function [X_norm, mu, sigma] = featureNormalize(X)

X_norm = X;
mu = zeros(1, size(X, 2));
sigma = zeros(1, size(X, 2));

for i = 1:size(X, 2)

    mu(i) = mean(X(:,i));
	sigma(i) = std(X(:,i));
	X_norm(:,i) = (X(:,i) - mu(i))/sigma(i);

end


end
